1. Technical Field
The following description relates to a liquid crystal display (LCD) device and a fabricating method thereof which are adapted to prevent light leakage due to external forces, simplify fabricating processes, and enhance response speed.
2. Discussion of the Related Art
Nowadays, a display field has been rapidly developed with the spread of an information society. In accordance therewith, flat panel display devices, including liquid crystal display (LCD) devices, plasma display panel device (PDPs), electroluminescence display devices (ELDs), field emission display devices (FEDs), and so on, have been introduced. Such flat panel display devices have rapidly replaced existing cathode ray tubes (CRTs) display devices and are in the spotlight because of their features, such as slimness, light weight, and low power consumption.
Among the flat panel display devices, the LCD devices are being most actively used in notebook computers, monitors, television receivers, and so on, because of displaying superior motion pictures and having a high contrast ratio.
The configuration of a conventional LCD device will now be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing a related art LCD device.
With reference to FIG. 1, the LCD device includes an LCD panel and a backlight unit 40 disposed under the LCD panel. The LCD panel includes an array substrate 10 and a color filter substrate combined in such a manner as to face each other with a liquid crystal layer 50 therebetween. One surface of a first substrate 10, referred to herein as the “array substrate,” is defined into pixel regions P. Also, the first substrate 10 includes a thin film transistor Tr and a transparent pixel electrode 19 which are provided in each of the pixel regions P. The thin film transistor Tr is connected to the transparent pixel electrode 19 through a contact hole which is formed in an interlayer insulation film 18. Such a thin film transistor Tr includes a gate electrode 12, a gate insulation film 13, an active layer 14, ohmic contact layer 15a, 15b, a source electrode 16, and a drain electrode 17.
A second substrate 24 opposite to the first substrate 10 with the liquid crystal layer 50 therebetween is referred to herein as an “upper substrate” or the “color filter substrate.” A black matrix 22 of a lattice shape is formed on one surface of the second substrate 24. The black matrix 22 is used as a screen for non-display elements, which include thin film transistors Tr of the first substrate 10 and so on, and expose only the transparent pixel electrodes. To this end, the black matrix 22 is formed in such a manner as to rim each of the pixel regions P.
Also, the second substrate 24 further includes red, green, and blue color filters 23 and a transparent common electrode 21. The red, green, and blue color filters 23 are arranged alternately with one another in the pixel regions P of the second substrate 24 which are defined by the lattice. The transparent common electrode 21 is formed to cover the black matrix 22 and the color filters 23.
Polarizing plates 11 and 25 are attached to outer surfaces of the first and second substrates 10 and 24. The polarizing plates 11 and 25 selectively transmit only fixedly polarized light.
A first alignment film 20a is interposed between the liquid crystal layer 50 and the pixel electrodes 19. Also, a second alignment film 20b is interposed between the liquid crystal layer 50 and the common electrode 21. One surface of each of the first and second alignment films 20a and 20b is rubbed in a fixed direction. Such first and second alignment films 20a and 20b enable an initial alignment state and an aligned direction of liquid crystal molecules to be uniformly maintained.
A seal pattern 70 is formed along edges of the first and second substrate 10 and 24. The seal pattern 70 is used to prevent a leakage of the liquid crystal material which is interposed between the first and second substrates 10 and 24.
Such an LCD device is not a self-luminous device. As such, a separate light source is necessary for the LCD device. In accordance therewith, the backlight unit 40 is disposed on the rear surface of the LCD panel and is used to apply light to the LCD panel.
The liquid crystal layer 50 used in the LCD device can include any one of a nematic liquid crystal material, a smectic liquid crystal material, a cholesteric liquid crystal material, and so on. However, the nematic liquid crystal material is mainly used in the liquid crystal layer 50 of the related art LCD device.
Meanwhile, the related art LCD device has a low response speed and causes a residual image to be visible. As such, the related art LCD device deteriorates the image quality. Moreover, many process steps are necessary to complete the related art LCD device. In view of these points, LCD devices each having a high response speed and enhancing process efficiency are being actively researched.